What will happened to those who use the mixer previously. Is there a chance that my Bitcoin will be connected by Bitcoin use from money laundering or we are still safe? I use Chipmixer every week to mix my coins. Its sad to read this bad news. 
I don't think that the users have any threat from this unless someone has been using the service for mixing the Bitcoins they got from some illegal activity and even in that case, I don't really think it's possible for them to track anyone down, or can they? I'm not entirely sure about that. But as long as you haven't done anything wrong, you should be okay.
It's really unfortunate, to be honest. I've been seeing chip mixer for years on this forum, and though I never used their services it is still sad to read this news and to see their website being seized.